docs: def _format_title_string(self, title_string):
          """ format vlc's title """
          sp = title_string.split(self.icy_tokkens[0])
          if sp[0] == title_string:
              ret_string = title_string
          else:
              ret_string = self.icy_title_prefix + sp[1]
          return self._title_string_format_text_tag(ret_string)